In bowl, toss spinach, mushrooms, and onions; season with salt and pepper. Layer
half of mozzarella cheese on top of dough; top with spinach mixture. Layer with
remaining mozzarella cheese.

Roll out 1/3 of dough to a 9-inch circle with pizza roller. Place on top of
pizza. Pinch together top and bottom crusts. Bake 35 min. Spread pizza sauce
over top; sprinkle with parmesan cheese. Bake an additional 10 min. Cool 10
min.; gently loosen and remove from baker to cutting board. Cut into wedges with
pizza cutter